Pen point



United States Patent Olce 3,467,478 Patented Sept. 16, 1969 3,467,478 PEN POINT Harold H. Webber, Groton, Mass., assignor to Brunswick Corporation, a corporation of Delaware Filed July 27, 1965, Ser. No. 475,217 Int. Cl. B43k 1/00, 1/08 U.S. Cl. 401-292 3 Claims ABSTRACT OF THE DISCLOSURE A pen point formed of a body of substantially rigid material, such as metal, having an end surface and a plurality of through passages opening through the end surface to deliver ink thereto for transfer onto a writing medium such as a paper surface. The passages have a mean diameter of under approximately mils, and are spaced apart a substantial distance such as at least approximately the mean diameter of the passages. The end surface may be provided with a layer of material differing from the material of the body, and may have different desired configurations, such as at, semispherical, etc. configurations. The passages may be uniformly distributed in the body or may be distributed in preselected nonuniform patterns as desired. The pen point effectively comprises a collimated hole structure which may be formed by constrieting a billet having a plurality of rods distributed therein, with the rods being suitably removed as by leaching upon completion of the constriction of the billet to the desired small size.

This invention relates to writing instruments and particularly to point constructions for use in pens and the like.

In one conventional form of writing instrument, Writing uid, such as ink, is applied to a writing surface, such as a paper surface, by means of a point structure having a plurality of iiow passages therethrough. The passages in one known such structure are formed by assembling a plurality of small diameter cylindrical elements, or rods, of a suitable material such as nylon in side-by-side parallel arrangement with the generally cusped cross-section interstices between the rods defining the desired ink flow passages. In another form of known pen point of this general construction, plant material, conventionally bamboo material, is employed, the pen point comprising hollow, generally hexagonally tubular passages formed by the dry residual cell walls which formed the fluid conducting channels of the living plant. In each of the indicated known pen point constructions, the respective passages are closely juxtaposed, being spaced from each other only by extremely small lines of Contact between the rod elements of the nylon point structure or the extremely thin cell Wall membranes in the plant material structure.

Another disadvantage of the known multi-passage pen point constructions is the low wearability of the pen point material, seriously limiting the useful life thereof. Still another problem found in the known multi-passage pen point structures is the difficulty of obtaining substantially uniform passage cross section. Still further with such known sructures it is difficult to obtain preselected desired nonuniform distribution patterns. Thus, the known multi-passage pen point structures, as discussed above, have not proven completely satisfactory and have found relatively limited use in the pen industry heretofore.

The present invention comprehends an improved pen point structure eliminating the disadvantages of the known multipassage pen point structures discussed above. Thus, the principal feature of the present invention is the provision of a new and improved pen point structure.

Another feature of the invention is the provision of such a pen point structure having a plurality of generally parallel -ink conducting passages having a pre-selected spaced distribution to provide improved writing characteristics.

A further feature of the invention is the provision of such a pen point structure comprising a body having a writing surface, a plurality of through flow passages opening at one end through the writing surface, each passage having a mean diameter of under approximately 10 mils, and the passages being spaced apart at least the mean diameter.

Still another feature of the invention is the provision of such a pen point structure wherein the passages are rounded in cross section.

A yet further feature of the invention is the provision of such a pen point structure wherein the passages are substantially rectilinear and extending in parallel side-byside relationship.

Yet another feature of the invention is the provision of such a pen point structure wherein the spacing between the passages is substantially greater than the mean diameter thereof.

A yet further feature of the invention is the provision of such a pen point structure wherein the passages have a length-to-mean-diameter ratio of at least 10.

Still another feature of the invention is the provision of such a pen point structure wherein the passages are uniformly transversely distributed.

Another feature of the invention is the provision of such a pen point structure wherein the passages are uniformly distributed as measured along the writing surface.

A further feature of the invention yis the provision of such a pen point structure wherein the passages have substantially equal cross sectional areas.

Still another feature of the invention is the provision of such a pen point structure wherein the passages have a deviation of cross sectional area of les than 3 percent.

A yet further feature of the invention is the provision of such a pen point structure wherein the cross sectional area of the passages decreases directly with the spacing thereof from the center of the writing surface.

Still another feature of the invention is the provision of such a pen point structure wherein the passages are rounded at the end thereof opening through the writing surface.

A yet further feature of the invention is the provision of such a pen point structure wherein the passages are transversely distributed in a pre-selected non-uniform distribution pattern.

A further feature of the invention is the provision of such a pen point structure wherein the body is formed of a metal, such as stainless steel, the passages being approximately 19 in number and having a mean diameter of approximately 3 mils, and said writing surface defines a full hemisphere having an outer circumference having a mean diameter of approximately M6 inch.

Another feature of the invention is the provision of such a pen point structure wherein the writing surface is provided with a layer of material different from the material forming said body.

A further feature of the invention is the provision of such a pen point structure wherein the body includes an integral cylindrical portion rearwardly of the writing surface.

Still another feature of the invention is the provision of such a pen point structure wherein the writing surface is convexly rounded.

Yet another feature of the invention is the provision of such a pen point structure wherein the writing surface is flat.

Other features and advantages will be apparent from 3 the following description of the accompanying drawing wherein:

FIGURE 1 is an end elevation of a pen point embodying the invention;

FIGURE 2 is a fragmentary side elevation thereof;

FIGURE 3 is a diametric section thereof with the pen point disposed in a writing position;

FIGURE 4 is a transverse section thereof;

FIGURE 5 is a diametric section similar to that of FIGURE 3 but of a modified form of pen point embodying the invention;

FIGURE 6 is an end elevation of a further modified form of pen point embodying the invention; and

FIGURE 7 is a transverse section thereof.

In the exemplary embodiment of the invention as disclosed in FIGURES 1 through 4 of the drawing, a pen point generally designated 10 is shown to comprise a body 11 of substantially rigid material, such as metal, having an end portion 12 provided with a distal, convexly rounded writing surface 13. Means for delivering writing fluid, such as ink, to the writing surface 13, and for transfer therefrom onto a writing medium, such as paper surface S, is provided in point 10 in the form of a plurality of passages, or channels 14, each having an outer end opening through the writing surface 13. Ink may be delivered to the passages 14 from a conventional supply or reservoir (not shown).

As indicated briefly above, the present invention comprehends an improved pen point structure, providing improved long life, smooth writing, free ow characteristics. More specifically, improved ink distribution on the writing surface 13 is provided in pen point 10 by substantially spacing the passages 14 from each other so as to provide substantial land area 16 between the respective passages 14, as best seen in FIGURE 1. In the illustrative embodiment the passages preferably have a mean diameter of under approximately 10 mils so as to provide improved regulated ink flow to the writing surface (mean diameter is defined herein as the diameter of a circle having a cross sectional area equal to the cross sectional area of the passage).

The spacing between the respective passages, is preferably atleast equal to approximately the mean diameter of the passages. In the illustrative embodiment the spacing between the passages is substantially twice the mean diameter of the passages. Still further, as the passages 14 open through the writing surface 13, which herein is convexly rounded, and more specifically herein is generally hemispherical, the spacing between the passages as measurred along the writing surface 13 is somewhat different from the transverse spacing between the passages, as illustrated in the diametric section of the pen point in FIG- URE 3. It is further preferable that the spacing between the openings 15 of the passages in writing surface 13 be spaced apart at least the mean diameter of the respective openings.

As best seen in FIGURE 3, the passages are rounded in cross section and may be generally circular in cross section. As shown in FIGURE 4, the passages 14 herein are longitudinally substantially rectilinear, extending through the body 11 in parallel side-by-side relationship. In the embodiment of FIGURES 1 through 4, the passages are substantially uniformly transversely distributed (as best seen in FIGURES 1 and 3). The passages 14 are illustrated in FIGURE 3 as having substantially equal cross sectional areas. However, as shown in FIGURE l, as the openings 15 are defined by the intersection of the generally right cylindrical passages 14 and the generally spherical surface 13, the cross section of the openings 15 varies in size directly as the spacing thereof from the central axis 17 of the point 10. Further, as best seen in FIGURE 1, the openings 15 become more elliptical as the spacing from the axis 17 increases with the opening 15a at the axis 17, being the sole truly circular opening.

For improved scratch-free writing characteristics, the corners 18 of the openings 15 may be rounded, i.e., pro- 4 vided with a radius, as by electro-polishing. If desired, the writing surface 13 may be formed as a layer of material differing from the material of which the remainder of the body 11 is formed. Illustratively, the surface 13 may comprise a gold-plated surface layer.

The length of the body 11 is preselected to provide a cylindrical portion 19 rearwardly of the hemispherical end portion 12, such as for use in supporting the pen point in the pen (not shown). The length of the passages 14 is substantially greater than the mean diameter thereof, and the invention comprehends a pen point structure wherein the length-to-mean-diameter ratio of the passages is at least equal to approximately 10.

In one specific embodiment of the invention found to provide an excellent pen point construction within the structural concepts comprehended by the invention, the body 11 is formed of stainless steel, such as type 304 stainless steel. The diameter of the body 11 is approximately iy inch with the passages having a mean diameter of approximately 3 mils and a spacing therebetween of approximately 6 mils. Nineteen passages are provided in a uniform transverse distribution.

Referring now to FIGURE 5, a modified form of pen point is shown to comprise a point generally similar to point 10 but having a writing surface 113 defined by a flat plane extending at an angle to the axis 117 of the point, herein at an angle of approximately 40 to 50 de grecs. Thus, point 110 provides a substantial writing surface area for facial engagement with the sur-faces to be written upon and thus is adapted for use in the conventional marking pen manner where a broad ink track is effected. In all other respects pen point 110 is similar to pen point 10 and functions in a similar manner.

Referring now to FIGURES 6 and 7, still another embodiment of the invention is shown to comprise a pen point generally designated 210, which is generally similar to pen point 10, but wherein the passages 214 vary in mean diameter, and in transverse distribution. The mean diameter of the respective passages may be, as shown, inversely related to the spacing of the passages from the central axis 217 of the point so that the openings 215 may be of effectively equal cross sectional area. Further, as illustrated in FIGURE 7, the area of the passages may be in a non-uniform, preselected distributional pattern to provide variation in the ink delivery to different portions of the writing surface 213 as desired. In all other respects pen point 210 is generally similar to pen point 10 and functions similarly thereto.

Pen points 10, 110 and 210 may be formed in a simple and economical manner by suitably constricting a billet having a plurality of rods distributed therein and in a distributional pattern and of a size proportional to the size of the passages 14 of the desired pen point. Upon constriction of the billet to the pen point size, the billet is cut into pen point lengths and the writing surface 13 formed on one end of the respective lengths. The writing surface 13 may be formed in any conventional, suitable manner, such as by grinding the end of the body 11, which may comprise a suitable cut end. The polishing of the writing surface may be conducted at this time or after the rods are suitably removed, leaving the passages 14 as disclosed above. The rods may be removed by leaching as where the rods are formed of a leachable material wherein the body is set. For a more detailed description of an excellent method of forming a multi-passage structure suitable for use as a pen point structure herein, reference may be had to co-pending John A. Roberts et al. U.S. patent application, Ser. No. 471,123, led July l2, 1965 and assigned to the assignee hereof.

I claim:

1. A pen point comprising a body having a substantially rigid writing surface, said body being formed of constricted material originally having a plurality of constricted elongated elements distributed therein which elements have been removed to define a plurality of through flow passages opening at one end through said Writing surface, each passage having a mean diameter of under approximately 10 mils, said passages being spaced apart at least said mean diameter and varying in cross-sectional area proportionally to the ratio of spacing from the center of said writing surface.

2. A pen point comprising a body having a substantially rigid surface, said body being formed of constricted material originally having a plurality of constricted elongated elements distributed therein which elements have been removed to dene a plurality of through ilow passages opening at one end through said writing surface, each passage having a mean diameter of under approximately 10 mils, said passages being spaced apart at least said mean diameter and decreasing in cross-sectional area directly with the spacing from the center of said Writing surface.

3. A pen point comprising a body having a substantially rigid surface, said body being formed of constricted material originally having a plurality of constricted elongated elements distributed therein which elements have been removed to dene a plurality of through flow passages opening at one end through said writing surface, each passage having a mean diameter of under approximately 10 mils, said passages varying in cross-sectional area proportionally to the ratio of spacing from the center of said Writing surface.

References Cited UNITED STATES PATENTS 416,659 12/1889 Wells et al 401-202 X 2,600,426 6/1952 Paul 40l-265 2,619,438 1l/1952 Varian et al 29--423 X 2,628,417 2/ 1953 Peyches 29-423 1,271,457 7/1918 Gaines l20-45.6 2,095,890 10/1937 Powell 120-109 2,891,272 6/1959 Wengeler et al. 15-601 3,203,025 8/1965 Schreur 15-563 FOREIGN PATENTS 1,160,331 2/1958 France.

807,468 1/ 1959 Great Britain.

ROBERT W. MICHELL, Primary Examiner Us. C1. X.R. 401-258, 265 

